1. Field of the Invention
The present invention relates to image data modification in an image data filing system for administering image data as coded data.
2. Description of the Background Art
An image data filing system for administering image data such as design drawings, documents, pictures, and maps in the form of coded data to be handled by a computer has come to be widely used in recent years. In such an image data filing system, it is necessary to accommodate modifications such as insertions and corrections, to be made on a particular portion of a particular image among a multiplicity of images filed in the system.
Conventionally, this has been achieved in one of the following ways.
A first manner is to make a modification on an original uncoded image, coding the modified image, and replacing the coded data before the modification with the coded data after the modification. However, in an image data filing system, the original image is normally not retained after the image had been coded and filed, so that this manner is scarcely used in a presently available image data filing system.
A second manner is to make a modification on a displayed image by means of a pointing device such as a light pen. However, it has been difficult for an average operator to maneuver such a pointing device with sufficient skills. In a case of computer aided designing (CAD), an operator has to specify a position to make a modification by means of a cursor on the displayed image, and, then, perform an operation to enter the desired modification, which is a quite tedious procedure.